Storage battery



Jan. 16, 1940.

J. ZERNIKE STORAGE BATTERY Filed June 26, 195'? gap/0m GRHPIHTE RUBBER HND GR/IPH/TE y g/ ASP/Ml Iii.

Patented Jen. 16, 1940 g 2,187,638

UNITED STATES PATENT OFFICE STORAGE BATTERY Johannes Zernike, Eindhoven, Netherlands, as-

signor to N. V. Philips Gloeilampeni'abrleken, Eindhoven, Netherlands Application June 26, 1937, Serial No. 150,626 In Germany July 13, 1936 2 (lams.V (Cl. 136-11) My invention relates to electric storage bat- Forming a marginal portion about 3 mms. wide teries, particularly multi-cell low-capacity storage around the edges of the plate and at both sides batteries using bipolar plates. thereof, is a coating 9 of asphalt, which may be 'Ihe term bipolar plates" is to -be understood formed by applying a solution of asphalt in bento mean plates which serve as a partition bezene. 8 tween adjacent cells, and have one surface act- The plate shown in Fig. 2 is the same as that ing as the negative plate of one cell and the opof Fig. 1 with the exception that the terminal 3 posite surface acting as the positive plate of the is located nearer the edge. adjacent cell. The plates are then inserted in the mold shown in Batteries of this type have been described in in Fig. 3 and comprising aeasins 6 (the front Side 10 detail in the British Patent #439,917, in which being indicated by dotted lines) having a Cere 5 the bipolar plates 'comprise graphite or a mix- Core 5 comprises a plurality of metal members ture of graphite and a non-conductive material I0 secured together by bolts Il and forming a such as artificial resin, whereas the electrolyte plurality of slots 4 which are closed at the botl consists of one or more soluble lead salts. tem. and SWO members l2 One 0f WhiCh iS DIO- u In the manufacture ot such batteries, considvided with a plurality Of hOleS I3 fOr reeeiVing erable difiiculty arises in securing a liquid-tight the terminals 3. construction; i. e. arranging the bipolar plates so The plates Shown in FIES- 1 and 2 are diSDOSed that there will be no communication between in the Slots 4 With the terminals 3 inserted in the cells around the edges of the bipolar plates. the holes I3. Liquid asphalt iS then DOilIed into 90 The object of my invention is to overcome the the mold to iill the residual hollow spaces and to l above diiiiculties, and for this purpose I form form a top layer. The mold is then named oi the plates from a mixture of graphite and ruband chilled. Core 5 is then removed by Iturning ber, and cast asphalt or a similar substance to SereWS 'l bearing 119011 the Side Portion 0f the form a container in which marginal portions of mold. after Which the Sides 0f the mold are re` 25 the plates are liquid-tightly embedded. moved.

I prefer to form the plates from rubber which, The battery is then provided with an electrodur-ing calendering, has had sufcient graphite lyte and for this purpose, as indicated in Fig. 4, added to give it the required conductivity. the spaces I5 between the plates are filled with To assist in obtaining a good seal at the edge a suitable porous material I6, such as cotton 30 portions of the plates, I prefer to provide the Wedding, glass wool or the like, which is soaked plates prior to casting of the condenser, with a with a solution of one or more soluble lead salts,

ridge or flange of asphalt. for instance lead silicium uoride, lead fluoborate,

In order that the invention may be clearly or the like.

understood and readily carried into eiect, I If the battery is provided with lead uosilicate 35 shall describe the same in more detail with refand then charged, lead peroxide will be deposited eren'ce to the accompanying drawing, in which: on one side of each plate, acting as an anode, and

Figures l and 2 are side views oi.' bipolar plates lead will be deposited on the other side of each according to the invention; plate, acting as a cathode. This action takes place 40 Fig. 3 is a partly-sectionized perspective view o! in accordance with the following formula and is 40 a mold for making the battery according to the reversible during the discharging: invention; and

o Fig. 4 is a partly-sectionized perspective view 2PbsiF.+2H.0 dlfslfgg rb-l-rbowznisir. of a completed battery according to the invention.

'I'he plate shown in Figure 1 comprises a sheet A layer of asphalt is then cast upon the top l of rubber and graphite having a thickness of to enclose and complete the battery ready for about 1/2 mm., and made from rubber to which charging. Such batteries are rechargeable, simeraphite has been added during calenderins, for pie, and inexpensive :to manufacture, which instance about 4-5 parts of powdered graphite t0 makes them particularly suitable as B batteries one par-t of rubber. Secured to the edge of the for radio work. 50

plate, for instance with lacquer, is a thin strip 2 `What 1 daim is: of copper, whereas a terminal 3 is riveted to strip 1. A secondary electric battery comprising a 2 and sheet l. The #terminal 3 is slotted at one cast container of asphalt, a plurality of plates end so as to nt over the plate, and is made tubucomprising a mixture of graphite and rubber and lar at its other end to receive a eonnectinz plus. having marginai portions cast into .the container or l, to form liquid tight compartments, the surface portions of Ithe plates bounding the compartments being adapted to receive active material Vto make the plates bipolar, and an electrolyte of a soluble lead salt Within said compartments.

2. A secondary electric battery comprising a cast container of asphalt, a plurality of plates comprising a mixture of graphite and rubber, said plates having marginal portions cast into the container to form: liquid-tight compartments,v 

